1. Field of the Invention
The present invention relates to a method for compressive packing in which an article, such as tow for tobacco filters, sanitary cotton, etc., which must be kept free of foreign matter, contamination and the biting effects of bundling belts, is packed continuously and automatically, and also relates to an apparatus for so packing an article.
2. Description of the Related Art
Articles having a small density and a large internal resiliency, such as chemical fibers, natural fibers and the like, are required to be compressively packed into a bale in a manner which prevents their contamination, the introduction of foreign matters thereto, and the biting effects of bundling belts due to forces generated thereby after they are compressed or due to the breakdown of packing materials. Such articles are typically packed with an adhered or laminated type of sheet consisting of a polypropylene Hessian cloth and a polyethylene sheet or with a kraft paper sheet having a polyethylene film lining. Thereafter, the outside of the wrapped article is protected with reinforcement members such as corrugated cardboard sheets or plastic sheets which exhibit excellent rigidity and strength. Then, the articles are bundled with bands or wires. Such method steps are carried out manually in the prior art.
Heretofore, a method of packing an article, such as tow (synthesized fibers) for tobacco filters, which has a small bulk density, and in which the introduction of foreign matters and the generation of contaminants must be prevented, consists of the following steps. First the article to be packed is compressively shaped from either or both of the upward and downward directions within a compressing box, whose upper and lower surfaces are opened and whose four side surfaces can be selectively opened or closed. Thereafter, the four side surfaces of the compression box are opened. Upper and lower reinforcements are then manually preliminarily mounted to upper and lower press seats of a compressive packing machine so as to be applied to the top and bottom of the article. The article is next manually wrapped with upper and lower wrapping materials, which wrapping materials are placed between the reinforcements and the article to be packed. Thereafter, two to four pieces of reinforcements are manually attached to the side surfaces of the article to be packed. Subsequently, the reinforcements are manually bundled by a number of bundling belts. Then the compressive forces on the articles are released.
In the following, one example of such a method for compressively packing tow made of acetate for use in tobacco filters will be described with reference to FIGS. 10 and 11. In these figures, FIG. 10(a) is a front view of a compressive packing machine in the prior art, and FIG. 11 is a cross-sectional view taken along line XI--XI in FIG. 10(a). In addition, FIG. 1 outlines a series of packing steps including the steps of wrapping, of mounting reinforcements and of manually bundling the reinforcements in a prior art compressive packing machine. It should be noted that although FIG. 1 has been prepared for describing the present invention, FIG. 1 will now be used for describing the manual steps in the prior art compressive packing method.
An article to be packed, such as acetate tow, is stored in an enclosure box 1 shown in FIG. 10. Thereafter the enclosure box is carried into the center of a compressive packing machine (FIG. 10a) by transport means such as a conveyor (not shown), and is positioned there by a positioning device 2.
Reinforcements 5a and 5b, such as corrugated cardboard sheets, kraft paper sheets or plastic sheets are manually mounted to an upper press seat 3 and a lower press seat 4 of the compressive packing machine jointly with flexible wrapping materials 6a and 6b such as an adhered or laminated sheet of polypropylene Hessian cloth and polyethylene via metal retainers 7a and 7b, respectively. It is to be noted that when the enclosure box 1 comes to the center of the compressive packing machine, the upper press seat 3 is at the upper limit (illustrated) position with the above-described reinforcement 5a and wrapping material 6a mounted thereto. The lower press seat 4 is located proximate the top of a fixed frame 8 (the upper limit position) with the reinforcement 5b and wrapping material 6b mounted thereto. And, large doors 10a and 10b and a small door 11 of a compressing box 9 are in a closed state. It is to be noted that the state depicted by double-dot chain lines of the large doors 10a and 10b in FIG. 11 is an opened state.
Under the above-described state, the enclosure box 1 is once lowered to a neutral position 13 by an enclosure box elevator 12 associated with the compressive packing machine. There a tow receiver 14 of the enclosure box 1 is opened by a tow receiver opening/closing device (not shown) disposed at the bottom of the enclosure box, and the enclosure box 1 is continuously lowered to a position at which the tow receiver 14 overlaps the top of the fixed frame 8 (the lower limit position). The lower press seat 4 is lowered by a hydraulic cylinder 16 or the like while supporting tow 15 within the enclosure box 1 via the reinforcement 5b and the wrapping material 6b, and comes to a lower limit position 17. Consequently, the tow 15 within the enclosure box 1, which is to be packed, is transferred into the compressing box 9 with a part thereof left within the enclosure box 1.
On the other hand, the upper press seat 3 is lowered by a hydraulic cylinder 18 or the like as accompanied by the reinforcement 5a and the wrapping material 6a, and compresses the tow 15 into the compressing box 9 under a predetermined compressing force until the tow assumes a predetermined height. Subsequently, the large doors 10a and 10b and the small door 11 of the compressing box 9 are opened either manually or automatically. And thereafter, the steps of wrapping the tow with the wrapping materials, of mounting the reinforcements and of bundling are carried out.
In the following, the above-described series of manual packing steps will be explained with reference to FIG. 1. In the compressive packing machine, after the tow 15 to be packed has been compressed within the compressing box 9 to the predetermined height with the predetermined compressing force, and the large doors 10a and 10b and the small door 11 have been opened, the tow is manually wrapped with the lower wrapping material 6b under the compressed condition of the tow block (FIG. 1(b)). This condition is maintained until the wrapping and bundling steps have been completed.
Subsequently, as shown in FIG. 1(c), the tow is manually wrapped with the upper wrapping material 6a in such a manner that the wrapping material 6a is overlapped with the upper edge of the lower wrapping material 6b. After the tow is wrapped with the upper and lower wrapping materials 6a and 6b, end portion treatments (folding) of the upper reinforcement 5a and the lower reinforcement 5b are manually carried out as shown in FIG. 1(d). (The ears of the respective reinforcements to be folded are denoted by 74a, 74b and 75a 75b, respectively.) Thereafter, as shown in FIG. 1(f), bundling belts 20 such as bands (or wires) are passed around the top, bottom and sides of the wrapped tow using band-(or wire-)passing grooves 3a of the upper press seat 3 shown in FIG. 10(b) and band-(or wire-)passing grooves 4a of the lower press seat 4 shown in FIG. 10(c) as guides. Thus, opposite end surfaces of the tow block are bundled. At this time, since the bundling belts 20 such as bands (or wires) loosely bundle the tow block (including the upper and lower wrapping materials), side surface reinforcements 19a and 19b are inserted into gaps between the bundling belts 20 and the tow block as shown in FIG. FIG. 1(f). And, in succession, end surface reinforcements 21a and 21b are manually applied to the tow block as shown in FIG. 1(g).
Subsequently, bundling belts 88 (bands or wires) are passed around the opposite ends of the tow block using passing grooves (not shown) extending perpendicular to the band-(or wire-)passing grooves 3a and 4a provided in the upper press seat 3 and the lower press seat 4. Then the tow block is released from the compressed condition (by the raising of the upper press seat 3), and expands to a state constrained by the bands (or wires). Thereafter, the opposite end portions 90a and 90b of the side surface reinforcements 19a and 19b are manually treated (folded) as shown in FIG. 1(h). Finally, the reinforcements are bundled by bands 22 to complete the formation of a compressively packed bale. Next, when the bale has been taken out of the compressive packing machine either manually or by a bale take-out device (not shown), a new reinforcement 5b and new packing material 6b are manually mounted to the lower press seat 4 and fixed thereto by means of a metal retainer 7b as shown in FIG. 10(b).
Successively, the hydraulic cylinder 18 is actuated by manipulating a push-button (not shown). Hence, its ram is lowered, and the upper press seat 3 descends to a level convenient for mounting the upper reinforcement 5a and the upper wrapping material 6a thereto. At this level of the upper press seat 3, the reinforcement 5a and the wrapping material 6a are manually mounted to the upper press seat 3 in a similar manner to that described above, and are fixed thereto by means of a metal retainer 7a.
After the above-described manual work has been finished, in response to a manipulation of a push-button (not shown), the upper press seat 3 is raised by the hydraulic cylinder 18 as accompanied by the reinforcement 5a and the wrapping material 6a, and the machine is restored to the state shown in FIG. 10(a). On the other hand, the bottom tow receiver 14 of the emptied enclosure box is closed, the enclosure box 1 is raised to the upper limit position by the elevator 12, the positioning device is opened, and the enclosure box 1 is transported to the outside of the compressive packing machine by a conveyor device (not shown), thereby completing one cycle of operation.
Next, an apparatus for bundling an article to be packed in the prior art will be explained with reference to FIGS. 18, 19 and 20. In these figures, reference numeral 101 generally designates a bundling apparatus including a head side portion 102 and a guide side portion 103 opposed to each other. The head side portion 102 is supported on a movable frame 105 which can be displaced by a cylinder 104. Also, there is a table 107 which can be made to advance or retreat by a cylinder 106. A plurality of bundling belt guides 108a of the head side portion 102 are fixed to a frame 115 jointly with a bundling machine 110. This bundling machine 110 (including the guides 108a) is movable by an electric motor cylinder 109. It is to be noted that reference numeral 102' in FIG. 19 designates a standby position of the head side portion 102.
In addition, a bale take-out conveyor 112 is movable by a cylinder 114, and is supported on movable table 105 so that it is also movable by cylinder 104. The guide side portion 103 includes a plurality of bundling belt guides 108b juxtaposed on a frame 119. This frame 119 is supported on a table 118 which can advance and retreat along a frame 116 as driven by a cylinder 117. Bale push-out pushers 120a and 120b are provided on frame 119.
When an article 123 is to be bundled, the bundling machine 110 and the bundling belt guides 108a of the head side portion 102 of the bundling apparatus 101 are advanced to position 108a', while the bundling belt guides 108b of the guide side portion 103 are advanced to the position 108b'. At these positions, bundling belts 125 such as bands are payed out from the bundling machine 10. The bundling belts 125 are wrapped around the article 123 to be packed as guided by the bundling belt guide 108a, bundling belt passing grooves 124 in an upper press seat 122a, the bundling belt guide 108b and bundling belt passing grooves 124 in a lower press seat 122b. Thus, the bundling belts 125 fasten and bundle the article 123 to be packed. More particularly, for each of the juxtaposed bundling belt guides, the bundling machine 110 sequentially advances, retreats and moves transversely by necessary amounts to apply the bundling belts 125 one by one.
When the article 123 to be packed has been bundled with the belts 125, the head side portion of the bundling apparatus 101 returns to its original position, the bundling machine 110 moves to position B , the bale take-out conveyor 112 moves to position A as interlocked with the former, the conveyor begins to rotate, the article 123 is pushed by the cylinder 114 to a receiving position proximate the conveyor, and the article 123 is loaded on the bale take-out conveyor 112 by a pushing member 126 operated by the bale push-out pushers 120a and 120b provided on the guide side portion 103. This conveyor 112 is once stopped, and then retracted by the cylinder 114 to its original position. Then, the article 123 is removed from the bundling machine and is sent to the next station.
However, in the above-described type of packing method in the prior art, in order to reduce the time of one cycle and to lighten a worker's load, it is necessary to preliminarily assemble the reinforcements 5a and 5b and the packing materials 6a and 6b into respective press seats and also to store them in a folded state for convenience. Accordingly there is a shortcoming in the prior art in that human labor for this work and a storage facility are necessary. In addition, although the mounting of the reinforcement 5b and the wrapping material 6b to the lower press seat 4 is not so laborious, the mounting of the reinforcement 5a and the wrapping material 6a to the upper press seat 3 requires the worker's face to be turned upward. And moreover, these materials typically weight several kilograms, so that such work necessitates considerable labor whereby the worker becomes very fatigued.
Furthermore, it is necessary to preliminarily cut the bands and wires (bundling materials) into predetermined lengths and to store them. Also since the mounting of the side surface reinforcements 19a and 19b is carried out manually, the labor of two to four workers is typically necessary, although this number depends upon the experience of the workers. Consequently, there are shortcomings in that there is a high degree of danger to human life during such manual work or in that the number of working mistakes is large. Moreover, the above-described operations have a very dangerous nature because all of such steps are carried out in the neighborhood of a press machine of several tens to several hundreds of tons. Finally, the appearance of packed articles according to the prior art largely depends upon the experience of the workers.
Still further, in the prior art, an article to be packed having a small bulk density and capable of generating a large resilient force was wrapped with flexible wrapping material such as a laminated or adhered sheet consisting of polypropylene Hessian cloth and a polyethylene sheet and the wrapped article was bundled with bundling belts either manually or automatically. But when the compressive force was released, the bundling belts would bite into the packed bale due to the tendency of the article to expand. Furthermore, the wrapping material would be broken as a result of this biting, in turn resulting in the contamination of the packed article or the introduction of foreign matters into the article. In addition, in the case where the packed article is unpacked for use, there is a problem in that twining, entangling or the like arises due to the biting of the bundling belts into the fibers of the article. Because of these problems, the article was bundled with bundling belts after reinforcements, such as corrugated cardboard sheets, had been applied to the outside of the wrapping materials.
FIG. 12 shows another prior art method of packing an article. In this figure, wrapping materials 130 such as sheets and reinforcements 131a and 131b are applied to the upper and lower surfaces of the tow block as shown in FIG. 12(a). Surface reinforcements 132 are applied as shown in FIG. 12(b). Then, only bundling belts 125 are applied as shown in FIG. 12(c). It is to be noted that the chain lines in FIG. 12(c) represent that the article is bundled sequentially with the bundling belts 125. FIG. 12(d) shows the appearance of a bundled package.
It is to be noted that a technique is known in which the article is wrapped with wrapping material 130 and has the upper surface reinforcement 131a and the lower surface reinforcement 131b automatically applied thereto. However, the side surface reinforcements 132 were applied manually by a plurality of workers in the direction shown by arrow x in FIG. 20, after the bundling was completed by the bundling machine, i.e. while the article 123 to be packed was in contact with the inner side surface bundling belts, but before a compressive force exerted on the article by the compressing machine was released. Since such work is carried out in the neighborhood of a large-size press machine, and also within an operating range of the bundling machine, it is of an extremely dangerous nature. In addition, since the other portions of the bundling apparatus are automated, a short cycle time can not be achieved because the above-noted manual operation acts as a neck in the cycle.